The Ugandan government was heavily criticised last year for its role in recruiting nurses and doctors to work abroad, and the country’s attorney general is currently facing a legal challenge over the episode. The level of opposition is unsurprising given the poor state of Uganda’s health system, including a scarcity of health professionals.

Other countries try to retain talented workers. Several have established programs to encourage highly skilled nationals to return from abroad. For example, Malaysia’s Returning Expert Programme gives preferential tax rates to returnees for five years, tax exemption for importing cars, and fast permanent residency for family members. Thousands have taken advantage of this opportunity but it still only manages to reverse a small fraction of the country’s total ‘brain drain’. And it is unclear how many of the participants would have returned to Malaysia anyway without the programme.

Considering, these opposing approaches to the emigration of professionals, it’s important to ask whether there are any conditions under which their departure can benefit a source country?

The key measure of the impact of emigration on human capital levels is not the number of educated individuals — doctors, nurses and so on — who leave the country, but the number who do not leave. These two numbers are related in multiple ways. If a country’s pool of talent were fixed, then the emigration of highly skilled workers would decrease its human capital. Yet evidence suggests that the departure of educated individuals is connected to the formation of more educated individuals. For instance, the possibility of leaving after getting an education and obtaining a higher pay abroad may encourage many people to go to school and university. As long as emigration remains moderate, the departure of some of the most educated may actually increase the levels of human capital in a country. Indeed, an extensive review of four decades of research in this area showed this to be the case. One study has suggested that the brain drain might have a negative effect if the highly educated emigration rate is above 20 per cent.

Evidence also suggests that those who leave can benefit their source country while they are abroad. The more educated emigrants are, the higher their salaries abroad, therefore the larger the remittances they send to their home economy. In some cases this can end up having a greater impact on the economy than if those professionals had never left.

The emigration of highly skilled professionals is not necessarily bad news for developing countries. Some emigration is a healthy thing, but too much can become problematic. This suggests that countries should put effort into maintaining the right balance between the emigration of professionals and incentives to stay — or return — home.